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Configuring interface settings for mstp, Interface settings for mstp, Mstp – LevelOne GTL-2691 User Manual

Page 262

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C

HAPTER

8

| Spanning Tree Algorithm

Configuring Interface Settings for MSTP

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C

ONFIGURING

I

NTERFACE

S

ETTINGS

FOR

MSTP

Use the Spanning Tree > MSTP (Configure Interface - Configure) page to

configure the STA interface settings for an MST instance.

CLI R

EFERENCES

"Spanning Tree Commands" on page 1061

P

ARAMETERS

These parameters are displayed:

MST Instance ID – Instance identifier to configure. (Default: 0)

Interface – Displays a list of ports or trunks.

STA Status – Displays the current state of this interface within the

Spanning Tree. (See

"Displaying Interface Settings for STA" on

page 255

for additional information.)

Discarding – Port receives STA configuration messages, but does

not forward packets.

Learning – Port has transmitted configuration messages for an

interval set by the Forward Delay parameter without receiving

contradictory information. Port address table is cleared, and the

port begins learning addresses.

Forwarding – Port forwards packets, and continues learning

addresses.

Priority – Defines the priority used for this port in the Spanning Tree

Protocol. If the path cost for all ports on a switch are the same, the port

with the highest priority (i.e., lowest value) will be configured as an

active link in the Spanning Tree. This makes a port with higher priority

less likely to be blocked if the Spanning Tree Protocol is detecting

network loops. Where more than one port is assigned the highest

priority, the port with lowest numeric identifier will be enabled.

(Default: 128; Range: 0-240, in steps of 16)

Admin MST Path Cost – This parameter is used by the MSTP to

determine the best path between devices. Therefore, lower values

should be assigned to ports attached to faster media, and higher values

assigned to ports with slower media. (Path cost takes precedence over

port priority.) Note that when the Path Cost Method is set to short

(page 3-63), the maximum path cost is 65,535.

By default, the system automatically detects the speed and duplex

mode used on each port, and configures the path cost according to the

values shown below. Path cost “0” is used to indicate auto-configuration

mode. When the short path cost method is selected and the default

path cost recommended by the IEEE 8021w standard exceeds 65,535,

the default is set to 65,535.